JPH09279070A - Ink for ink jet recording and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink for ink jet recording which gives a high-quality print without causing mixed-color blur by incorporating a polyvalent metal salt and a water-sol. low-volatility org. solvent into an ink compsn. contg. a magenta dye. SOLUTION: In this method, two types of ink: magenta ink contg. a polyvalent metal salt and black ink contg. a pigment and a resin emulsion and/or an inorg. oxide colloid, are simultaneously used for printing. The magenta dye is represented by formula I (wherein A is a phenyl or naphthyl group having a sulfone group; R is H, acetyl, -COC6 H5 , -COC6 H4 CH3 ; and M is an alkali metal, ammonium, an org. amine group, or an alkyl group) and is added in an amt. of 0.5-25wt.% of the magenta ink. The salt is pref. a nitrate or carboxylate. The solvent is glycerin and/or 2-pyrrolidone and is used in an amt. of 5-40wt.%. The wt. ratio of the sum of the dye and the salt to the solvent is (1:0.5)-(1:4). An example of the resin emulsion is an acrylic resin emulsion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording method, and more specifically, to an inkjet recording ink and recording method capable of achieving high-quality printing without causing color mixture bleeding (hereinafter referred to as color bleed) on plain paper. Regarding

(Background Art) An ink jet recording method is
This is a printing method in which small droplets of the ink composition fly and adhere to a recording medium such as paper to perform printing. This method has a feature that high-resolution and high-quality images can be printed at a high speed with a relatively inexpensive device. In general, ink used for ink jet recording mainly contains water, and further contains a coloring component and a wetting agent such as glycerin for the purpose of preventing clogging.

On the other hand, as an ink jet recording method, recently, a method of combining a color ink composition containing a metal salt solution and a black ink containing a pigment has been proposed. (JP-A-6-106735) In this method, the viscosity of the black ink containing the metal salt and the pigment increases.
It is said that high black character quality can be obtained even on plain paper by causing agglomeration.

[0004]

SUMMARY OF THE INVENTION The present inventors have now developed a magenta ink containing the above polyvalent metal salt, a pigment, a resin emulsion, and / or
Further, it was found that a black ink containing an inorganic oxide colloid is simultaneously brought into contact with a recording medium to cause thickening and aggregation, and a good image can be realized.

The ink jet recording method according to the present invention is an ink jet recording method for simultaneously printing a magenta ink containing a polyvalent metal salt and a black ink containing a pigment, a resin emulsion and / or an inorganic oxide colloid.

[0006]

[Detailed Description of the Invention]

(Inkjet recording method) The inkjet recording method according to the present invention simultaneously prints a magenta ink containing a polyvalent metal salt and a black ink containing a pigment, a resin emulsion and / or an inorganic oxide colloid.

Originally, the dye tends to be salted out with a metal salt to form an insoluble complex. However, it is possible to obtain a color ink without forming an insoluble complex by simultaneously containing a specific dye, a specific metal salt, and a specific water-soluble low-volatile organic solvent.

Further, even if a monovalent salt is used as the metal salt, there is almost no effect, so that a specific polyvalent metal salt having a valence of 2 or more is used.

According to the ink jet recording method of the present invention, the color ink, the pigment, the black ink containing the resin emulsion and / or the inorganic oxide colloid are brought into contact with each other on the recording medium to cause thickening / aggregation, and thus the black ink. The fast and reliable fixing onto the recording medium can be obtained, and good printing can be performed.

(Ink Composition) The magenta ink used in the present invention contains at least one dye represented by the following general formula (I), and further comprises a polyvalent metal salt and a water-soluble low-volatile organic solvent. .

[0011]

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(Wherein A is a phenyl group or a naphthyl group having at least one sulfone group, --SO ₃ M,
_{-CH 3, -NHCOCH 3, -OCH 3} , may be substituted with -NO _3. R is -H, -COCH _3, -COC
₆ H _6, is -COC ₆ H ₅ CH _3. M is an alkali metal,
Ammonium, organic amines, and alkyl groups. The compound of the general formula (I) used in the present invention may be of any type, and particularly preferred specific examples include the following. Also, two or more of these may be used at the same time.

[0013]

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[0014]

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[0015]

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[0016]

[Chemical 6]

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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The content of the dye as shown above is determined depending on the kind of the solvent component, the characteristics required for the ink, etc., but in the case of forming an image by the ink jet recording system, it is 0.5 to 6% by weight, preferably 1-5% by weight
Range.

The polyvalent metal salt is preferably a nitrate or a carboxylate, specifically Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Z.
n ²⁺ , Ba ²⁺ divalent metal ions, Al ³⁺ , Fe ³⁺ , Cr
Salts of ³⁺ trivalent metal ions may be mentioned, among which C
The metal salt composed of a ²⁺ or Mg ²⁺ gives favorable results from the two viewpoints of the pH of the magenta ink and the quality of the obtained print.

The concentration of these polyvalent metal salts in the magenta ink may be appropriately determined within the range where the effect of printing quality and clogging prevention can be obtained, but it is preferably about 0.1 to 40% by weight, more preferably Is about 5 to 25% by weight.

The water-soluble low-volatile organic solvent contains glycerin and / or 2-pyrrolidone.

The amount added is 5 to 40% by weight, preferably 10
Is about 30 to 30% by weight, and the weight ratio of the sum of the amounts of the dye and the polyvalent metal salt to the water-soluble low-volatile organic solvent is 1: 0.
It is 5 to 1: 4, preferably 1: 1 to 1: 2.

The black ink used in the present invention comprises a pigment and a resin emulsion or an inorganic oxide colloid.

As the pigment, an inorganic pigment or an organic pigment can be used without particular limitation. As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnest method or a thermal method can be used. Examples of organic pigments include azo dyes (including azo lakes, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc.), and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines) Pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, etc., dye chelates (eg, basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.

The amount of pigment added to the ink is 0.5 to 25.
% By weight, more preferably 2 to 15% by weight.
It is a degree.

A resin emulsion and / or an inorganic oxide colloid is preferably added to the ink of the present invention. The resin emulsion means an emulsion in which the continuous phase is water and the dispersed phase is the following resin component.
As the resin component of the dispersed phase, acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, butadiene resin,
Examples include styrene resins.

According to a preferred embodiment of the present invention, this resin is preferably a polymer having both a hydrophilic portion and a hydrophobic portion. Further, the particle size of these resin components is not particularly limited as long as an emulsion is formed.
It is preferably not more than about 5 nm, more preferably about 5 to 100 nm.

These resin emulsions can be obtained by mixing resin particles with water, optionally together with a surfactant. For example, an acrylic resin or styrene-acrylic resin emulsion is prepared by adding (meth) acrylic acid ester or styrene, (meth) acrylic acid ester, and optionally (meth) acrylic acid ester, and a surfactant to water. It can be obtained by mixing. The mixing ratio of the resin component and the surfactant is usually preferably about 10: 1 to 5: 1. If the amount of the surfactant used is less than the above range, it is difficult to form an emulsion, and if it exceeds the above range, the water resistance of the ink tends to decrease and the penetrability tends to deteriorate. The surfactant is not particularly limited, but preferable examples include anionic surfactants (eg, sodium dodecylbenzenesulfonate, sodium laurate, ammonium salt of polyoxyethylene alkyl ether sulfate, etc.), nonionic surfactants ( Examples thereof include polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc. A mixture of two or more species can be used.

The proportion of the resin and water as the disperse phase component is in the range of 60 to 400 parts by weight of water, preferably 100 to 200 parts by weight, based on 100 parts by weight of the resin.

It is also possible to use a commercially available resin emulsion, for example, Microgel E-100.
2, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001
(Acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.) Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.), SAE-1014 (styrene-acrylic resin emulsion, Nippon Zeon Co., Ltd.) Made), Cybinol S
K-200 (acrylic resin emulsion, manufactured by Saiden Chemical Co., Ltd.) and the like.

The ink used in the present invention preferably contains a resin emulsion so that the resin component accounts for 0.1 to 40% by weight of the ink, and more preferably 1 to 2.
It is in the range of 5% by weight.

The resin emulsion has the property of thickening and aggregating by the interaction with the polyvalent metal salt, and has the effect of suppressing the penetration of the coloring component and further promoting the fixing to the recording material. Further, depending on the type of resin emulsion, a film is formed on the recording material, which has the effect of improving the abrasion resistance of the printed matter.

Specific examples of the inorganic oxide colloid include colloidal silica and alumina colloid. Various types of these are commercially available as colloidal solutions in which ultrafine particles such as SiO2 and Al2O3 are dispersed in water or an organic solvent. Examples of commercially available products include
The dispersion solvent is water, methanol, 2-propanol, n-propanol, xylene, etc., and SiO2, Al2O3
It is general that the particle diameter of such particles is 5 to 100 nm. In many cases, the pH of the inorganic oxide colloid solution is adjusted not to the neutral region but to acidic or alkaline. This is because the stable dispersion region of the inorganic oxide colloid exists on the acidic side or the alkaline side, and when added to the ink, the pH of the stable dispersion region of the inorganic oxide colloid and the pH of the ink are taken into consideration. Need to be added.

Specific examples of the inorganic oxide colloid that can be used in the present invention include colloidal silica and alumina colloid, but the colloid that can be used is not limited to these. The inorganic oxide colloid that can be used in the present invention is a dispersion solvent, the type of inorganic oxide, particle size, p
Although there is no particular limitation on H and the like, any one can be used as long as it has a property of interacting with a polyvalent metal salt to thicken / aggregate and in which the inorganic oxide particles are stably dispersed.

The inorganic oxide colloid in the ink used in the present invention is preferably such that the inorganic oxide is 0.1 to 15% by weight of the ink, and two or more kinds may be added.

According to a preferred embodiment of the present invention, the pigment is
The pigment is preferably added to the ink as a pigment dispersion obtained by dispersing the pigment in an aqueous medium with a dispersant. As a preferable dispersant, a known dispersant used for preparing a conventionally known pigment dispersion liquid can be used.

For example, polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, Styrene-methacrylic acid copolymer, styrene-acrylic acid-acrylic acid alkyl ester copolymer,
Styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer Coalescence, vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer,
Examples thereof include vinyl acetate-acrylic acid copolymer.

According to a preferred embodiment of the present invention, these copolymers have a weight average molecular weight of 3,000 to 50,000.
Is preferable, and more preferably 5,000 to 3
000, most preferably 7,000 to 15,000
It is.

The addition amount of the dispersant may be appropriately added as long as the pigment is stably dispersed and the other effects of the present invention are not lost. According to a preferred embodiment of the present invention, the amount of the pigment: dispersant used is preferably 1: 0.06 to 1: 3, more preferably 1: 0.125 to 1: 3.

The organic solvent contained in the ink composition is
A low boiling point organic solvent is preferable, and preferable examples thereof include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, and s.
Examples include ec-butanol, tert-butanol, iso-butanol, and n-pentanol. A monohydric alcohol is particularly preferable. The low boiling point organic solvent has the effect of shortening the ink drying time.

The ink composition used in the present invention preferably further contains a high boiling point organic solvent. Preferred examples of the high boiling point organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, triethylene glycol, polypropylene glycol, 1,2,6-hexanetriol, thioglycol, and Polyhydric alcohols such as xylene glycol, glycerin, trimethylolethane, trimethylolpropane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monomethyl ether Ethylene glycol monoethyl ether, triethylene glycol Alkyl ethers of polyhydric alcohols such as mono butyl ether, urea, N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like.

The amount of the low boiling point organic solvent added is 0.5 to 10% by weight of the ink composition, more preferably 1.5 to 6% by weight.
Is appropriate. The amount of the high boiling point organic solvent added is in the range of 0.5 to 40% by weight, preferably 2 to 20% by weight of the ink composition.

The ink composition used in the present invention may contain a surfactant. Examples of this surfactant include anionic surfactants (for example, sodium dodecylbenzenesulfonate, sodium laurate, ammonium salt of polyoxyethylene alkyl ether sulfate), nonionic surfactants (for example, polyoxyethylene alkyl). Ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether,
Polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc.), acetylene glycol (olefin Y, and Surfynol 82, 104, 44)
0, 465, and 485 (all Air Products and
Chemicals Inc.))) can also be used.

According to a preferred embodiment of the present invention, the ink composition preferably contains sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, Lactose, sucrose, trehalose, maltotriose and the like can be mentioned. Here, the polysaccharide means a sugar in a broad sense, and is meant to include substances widely existing in the natural world such as α-cyclodextrin and cellulose.

The derivatives of these saccharides include reducing sugars of the above-mentioned saccharides (for example, sugar alcohol (general formula H
It is represented by OCH2 (CHOH) nCH2OH (where n represents an integer of 2 to 5). ), Oxidized sugar (eg, aldonic acid, uronic acid, etc.), amino acid, thioacid, etc. In particular, sugar alcohols are preferred, and specific examples include maltitol and sorbitol.

The content of these saccharides is appropriately in the range of 0.1 to 40% by weight, preferably 0.5 to 30% by weight of the ink composition.

If necessary, a pH adjusting agent, a preservative, a fungicide, etc. may be added.

[0052]

The present invention will be described in more detail with reference to the following examples, but it should not be construed that the invention is limited thereto.

(Preparation of Magenta Ink Composition) The following components except the polyvalent metal salt are mixed, and then the polyvalent metal salt is mixed. Then, filtration was performed with a membrane filter having an average pore diameter of 0.8 μm to obtain an ink composition.

(Magenta Ink Composition 1) Exemplified Dye (M-5) 4% by Weight Surfynol 465 (Air Products and Chemicals In
c.) 0.7% by weight diethylene glycol monobutyl ether 3% by weight diethylene glycol 4% by weight glycerin 12% by weight triethanolamine 0.9% by weight magnesium nitrate hexahydrate 5% by weight ion exchanged water remaining amount (magenta ink composition) Item 2) Exemplified dye (M-9) 3% by weight Surfynol TG (Air Products and Chemicals Inc.
0.8% by weight diethylene glycol monobutyl ether 10% by weight diethylene glycol 20% by weight glycerin 10% by weight triethanolamine 0.9% by weight magnesium nitrate hexahydrate 5% by weight ion-exchanged water residual amount (magenta ink composition 3) ) Exemplified dye (M-3) 3% by weight Diethylene glycol 5% by weight Glycerin 10% by weight 2-Pyrrolidone 5% by weight Magnesium acetate tetrahydrate 4% by weight Ion-exchanged water residual amount (magenta ink composition 4) Exemplified dye ( M-5) 4% by weight Surfynol 465 0.7% by weight Diethylene glycol monobutyl ether 3% by weight Diethylene glycol 4% by weight Glycerin 12% by weight Triethanolamine 0.9% by weight Sodium nitrate 5% by weight Ion-exchanged water remaining amount (magenta ink) composition 5) Exemplified dye (M-1) 3% by weight Diethylene glycol 20% by weight Magnesium acetate / tetrahydrate 4% by weight Ion-exchanged water Remaining amount (Preparation of black ink composition) Carbon black and a dispersant are mixed, and a sand mill is used. In (Yasukawa Seisakusho), glass beads (diameter 1.7 mm, 1.5 times amount (weight) of the mixture) were dispersed together for 2 hours. After that, the glass beads were removed, other additives were added, and the mixture was stirred at room temperature for 20 minutes. Filter through a membrane filter with an average pore size of 5 μm,
An ink composition was obtained.

(Black ink composition 1) Carbon black MA7 5% by weight (manufactured by Mitsubishi Kasei Co., Ltd.) Styrene-acrylic acid copolymer 1% by weight (dispersant) Boncoat 4001 50% by weight (acrylic resin emulsion, resin component) 50%, MF
T = 5 ° C., manufactured by Dainippon Ink Co., Ltd.) Sucrose 0.7% by weight Maltitol 6.3% by weight Glycerin 10% by weight 2-Pyrrolidone 2% by weight Ethanol 4% by weight Ion-exchanged water Remaining amount (black ink composition 2) Carbon black Raven 1080 5% by weight (Colombyan Carbon Co., Ltd.) Styrene-acrylic acid copolymer 1% by weight (dispersant) Microgel E-5002 0.35% by weight (styrene-acrylic emulsion, resin component 29.
2%, MFT = about 80 ° C., manufactured by Nippon Paint Co., Ltd.) Snowtex S 3.5% by weight (colloidal silica, SiO2 component 30%, manufactured by Nissan Kagaku) Sucrose 0.7% by weight Maltitol 6.3% by weight Glycerin 10% by weight 2-pyrrolidone 2% by weight Ion-exchanged water Remaining amount (black ink composition 3) C.I. I. Food Black 2 3% by weight Glycerin 5% by weight Ethanol 4% by weight The magenta ink composition and the black ink composition shown above were combined in the following manner, and actual printing was performed with an inkjet printer to evaluate the printing quality and the like.

(Example 1) A case where the magenta ink composition 1 and the black ink composition 1 were combined.

(Example 2) A case where the magenta ink composition 2 and the black ink composition 1 were combined.

(Example 3) A case where the magenta ink composition 3 and the black ink composition 2 were combined.

Comparative Example 1 This is a case where the magenta ink composition 1 and the black ink composition 3 were combined.

Comparative Example 2 This is a case where the magenta ink composition 4 and the black ink composition 2 were combined.

Comparative Example 3 This is a case where the magenta ink composition 5 and the black ink composition 1 were combined.

<Evaluation 1: Print quality (color bleed)>
Inkjet printer MJ-800C (manufactured by Seiko Epson Corporation) was used to print on each of the following plain papers.
The printing pattern is 100% duty for magenta ink.
So, the black ink printed characters at the same time. After drying,
The presence or absence of bleeding in letters was examined. Xerox P paper (manufactured by Xerox Co., Ltd.) Ricopy 6200 paper (manufactured by Ricoh Co., Ltd.) Xerox 4024 paper (manufactured by Xerox Co., Ltd.) Neenah Bond paper (manufactured by Kimberley Clark Co.) Xerox R paper (manufactured by Xerox Co., Ltd.) Yamayuri paper (Recycled paper manufactured by Honshu Paper Co., Ltd.) The results are shown in the table. In the case of clear printing without bleeding- ○ When whisker-like bleeding occurs- △ When bleeding occurs so that the outline of the character is not clear-x <Evaluation 2: Clogging> Inkjet printer MJ
-500C (Seiko Epson Corp.) ink cartridge was filled with the specified magenta ink, and after printing alphanumeric characters continuously for 10 minutes, the printer was stopped and the temperature was kept at 40 ° C and 25% without cap. It was allowed to stand for 2 weeks in the RH environment. After leaving, the alphanumeric characters were printed again, and the number of times of the clogging recovery operation required until the print equivalent to that before leaving was obtained was examined. Printing that is the same as the initial printing is possible with 0 to 2 times of the returning operation.- ○ Printing that is the same as the initial printing is possible with the returning operation of 3 to 5 times.
×

[0063]

[Table 1]

Claims (6)

[Claims] 1. An ink jet recording comprising an ink composition containing at least a magenta dye, wherein the ink composition comprises a polyvalent metal salt and a water-soluble low-volatile organic solvent. Ink. 2. The ink for ink jet recording according to claim 1, wherein the magenta dye contains one or more dyes represented by the following general formula (I). Embedded image (In the formula, A is phenyl group or a naphthyl group having at least one sulfone _{group, -SO 3 M, -CH 3,} -
NHCOCH _3, -OCH _3, may be substituted with -NO _3. R is _{-H, -COCH 3, -COC 6 H} 6, -COC 6
It is H ₅ CH _3. M is an alkali metal, ammonium, an organic amine, or an alkyl group. ) 3. The ink jet recording ink according to claim 1, wherein the polyvalent metal salt is a nitrate or a carboxylate. 4. The ink jet recording ink according to claim 1, wherein the water-soluble low-volatile organic solvent is glycerin and / or 2-pyrrolidone. 5. The water-soluble low-volatile organic solvent is 5-40.
The content of the dye and the polyvalent metal salt is in the range of 1% by weight and the weight ratio of the water-soluble low-volatile organic solvent is 1:
The ink for inkjet recording according to claim 1, which is 0.5 to 1: 4. 6. A black ink containing a pigment, a resin emulsion and / or an inorganic oxide colloid, and the color ink according to any one of claims 1 to 4 are attached to a recording medium to form a recorded image. Inkjet recording method.